Previously, our group identified the crucial role of T cell-intrinsic IL-18R/MyD88 signaling for the reinforcement and maintenance of the Th1 program in vivo, in response to mouse infection with Trypanosoma cruzi, in which Th1 cells have a key protective function (Oliveira et al., 2017; Rodrigues et al., 2012). The gene discussed is MYD88; the disease is infection.